Large B-cell Lymphoma Manifesting as an Invasive Cardiac Mass: Sustained Local Remission after Combination of Methotrexate and Rituximab

Cardiac tumor is an infrequent but serious manifestation of lymphoma and optimal management has not been well defined in these rare cases. Here we describe a patient who after autologous transplant for large B-cell lymphoma, relapsed with an invasive cardiac tumor, infiltrating the full thickness of the right myocardial wall. During therapy, she developed hemodynamic collapse due to complex atrial arrhythmias and had to be treated and stabilized in the intensive cardiac care unit. Despite initial significant regression of the cardiac tumor, new extranodal sites of lymphoma soon appeared in the skin, stomach and nervous system. Because of poor compliance, she was given salvage therapy with weekly four I.V. infusions of methotrexate and rituximab followed by monthly four maintenance cycles of rituximab alone. This produced an unexpected prolonged complete remission lasting 12 months, but she then developed a fatal leukemic phase. The relapse spared the heart and no cardiac abnormality was evident clinically or by any imaging technique. To the best of our knowledge this case, unique in terms of tumor size and extent of invasion, represents the first report of the treatment of invasive cardiac lymphoma using a combination of modest chemotherapy and rituximab.